• Journal of the Korean Ceramic Society
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• v.34 no.10
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• pp.1074-1082
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• 1997

Microstructure and permeability as a function of sintering temperature and composition were studied on the Ni$\delta$Cu0.4-$\delta$Zn0.6Fe2O4 ($\delta$=0, 0.1, 0.2, 0.3, 0.4) which was prepared by Cu2+ substitution for Ni2+ in Ni.0.4Zn0.6Fe2O4, then followed by 8 wt% CuO and 1wt% Bi2O3 as sintering aids. It was found that NiCuZn ferrite in which Cu2+ is substituted for Ni2+ is more effective in reduction of sintering temperature than Ni.0.4Zn0.6Fe2O4, containing CuO as a sintering aid. The specimen $\delta$=0.2 sintered at 90$0^{\circ}C$ for 2hr exhibited the highest initial permeability value ($\mu$o=280 at 1Mhz), but the real permeability decreased at the frequency under 10 MHz. EPMA analysis showed that Ni$\delta$Cu0.4-$\delta$Zn0.6Fe2O4 ($\delta$=0.4), sintered at 95$0^{\circ}C$ for 2hrs consisted of three phase regions of Ni.0.3Cu0.1Zn0.6Fe2O4 region, Cu and Bi liquid existed at the 3-point boundary, although the stabilization energy of Ni2+ is higher than that of Cu2+ in B site.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.4
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• pp.281-292
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• 2004

This pot experiment was conducted to investigate the effects of systematic variation appling of Fe, Mn, Cu, and Zn on forage performance of orchardgrass and white clover, The treatments of systematic variation were 0/100. 25/75, 50/50. 75/25, and $100/0\%$ in the Fe/Cu, Mn/Zn, and Fe+Cu/Mn+Zn trials, respectively. The treatments of Fe/Mn/Cu/Zn trial were $70\%$ in main-element and $10\%$ in other 3sub-elements. 1 . General differences had been showed in the relative contents, uptake amounts, and mutual ratios of Fe, Mn, Cu, and Zn between orchardgrass and white clover. The effects of Fe application on the all traits were generally insignificant. The Mn and Cu applications, however, showed consistent differences in the all traits. At the high relative content of Mn in the forages influenced by the Mn application, the relative contents of Fe, Cu and Zn were greatly decreased without the significant differences in common content. 2. The increase of uptake amount of each micronutrient was not positively correspond to the yield increase. In some cases, the uptake amount of micronutrient was greatly increased without the significant increase of yield. At the Mn application, the Mn uptake amount was relatively much more increased than increase of the yield. The uptake amount of each element was significantly increased by the application with Mn and Cu. However, it was not in the case of Fe and Zn. 3. The mutual ratios of micronutrients were more influenced by the applications of Mn and Cu, especially Mn, than those by the applications of Fe and Zn. In the Fe/cu trial, the ratios of Fe/Cu showed 6.0~ 10.5 in orchardgrass and 10.2~ $16.4\%$ level of difference in white clover. In the Fe+Cu/Mn+Zn trial, the ratios of Mn/Cu, Mn/Zn, and Fe/Mn were greatly influenced by the treatments. It has been also found that the poor growth of white clover was caused by the unbalanced ratios of Fe/Mn, and it tended to be enhanced by the good applications and mutual ratios of other elements.

• Journal of Korea Foundry Society
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• v.35 no.4
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• pp.67-74
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• 2015

In this study, Mg-Zn alloys are investigated in terms of their thermal properties after an addition of Cu. Al element is added to improve the mechanical properties and castability in general case. However, it was excluded here because it significantly decreases the thermal conductivity. On the other hand, Zn was added as a major element, which had less influence on reducing the conductivity and can complement the mechanical properties as well. Cu was also added, and it improved the heat transfer characteristics as the amount was increased. The composition ranges of Zn and Cu are 6 wt.% and 0~1.5 wt.%, respectively. Mg-6Zn-xCu alloy was prepared by a gravity casting method using a steel mold and then the thermal conductivity and the microstructure of the as-cast material were investigated. By measuring the density_(${\rho}$), specific heat_(Cp) and thermal diffusivity_(${\alpha}$), the thermal conductivity_(${\lambda}$) was calculated by the equation ${\lambda}={\rho}{\cdot}Cp{\cdot}{\alpha}$. As the amount of Cu increased in the Mg-6Zn-xCu alloy, the heat transfer characteristics were improved, resulting in a synergistic effect which is slow when the added Cu exceeds 1 wt.%. In order to investigate the relative thermal conductivity/emission of the Mg-6Zn-xCu alloy, AZ91 and AZ31 were experimentally evaluated and compared using a separate test equipment. As a result, the Mg-6Zn-1.5Cu alloy when compared to AZ91 showed improvements in the thermal conductivity ranging from 30 to 60% with a nearly 20% improvement in the thermal emission.

• Journal of the Microelectronics and Packaging Society
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• v.9 no.4
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• pp.47-53
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• 2002

In this study, two different (NiCuZn)-ferrite which were fabricated by using ultra-fine powders synthesized by the wet processing and conventionally commercialized powder, were investigated and compared each other in terms of the low temperature sintering and electromagnetic properties. Composition of x and w in $(Ni_{0.4-x}Cu_xZn_{0.6})_{1+w}(Fe_2O_4)_{1-w}$ were controlled as 0.2 and 0.03, respectively. The sintering temperature were $900^{\circ}C$ for ultra-fine powders by way of initial heat treatment and $1150^{\circ}C$ for commercialized powders. The (NiCuZn)-ferrite by ultra-fine powders showed love. sintering temperature than that of commercialized powders by over $200^{\circ}C$, and excellent electromagnetic properties such as the quality factor which is a important factor in the multi-layered chip inductor. In addition, characteristics of B-H hysteresis, crystallinity, microstructure and powder morphology were analyzed by a vibrating sample method(VSM), x-ray diffractometer(XRD), transmission electron microscope (TEM) and scanning electron microscope(SEM).

• Journal of the Korean Magnetics Society
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• v.3 no.1
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• pp.18-22
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• 1993

The cationic distributions and magnetic properties of $Cu_{x}Zn_{1-x}Fe_{2}O_{4}(0{\leq}x{\leq}1)$ have been studied by X-ray diffraction and $M\"{o}ssbauer$ spectroscopy. The crystal structures are cubic spinels in the range $0{\leq}x{\leq}0.9$. The ionic distribution of ${(Zn_{1-x}Fe_{x})}_{A}{[Zn_{x}Fe_{2-x}]}_{B}O_{4}$, where x=0.1. The distribution of $Fe^{3+}$ ions was extracted from the $M\"{o}ssbauer$ spectra below Curie temperature in the whole range $0{\leq}x{\leq}1$. The number of $Fe^{3+}$ ions in the tetrahedral sites and Curie temperature of Cu-Zn ferrite increase with increasing Cu-concentration.

• Proceedings of the KWS Conference
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• 2005.11a
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• pp.219-221
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• 2005

Sn-9Zn solder balls were bonded to Cu, ENIG (Electroless Nickel/Immersion Gold) and electrolytic Au/Ni pads, and the effect of aging on their joint reliability was investigated. The interfacial products were different from the general reaction layer formed in a Sn-base solder. The intermetallic compounds formed in the solder/Cu joint were $Cu_{5}Zn_{8}$ and $Cu_{6}Sn_{5}$. After aging treatment, voids formed irregularly at the bottom side of the solder because of Sn diffusion into the $Cu_{5}Zn_{8}$ IMC. In the case of the solder/ENIG joint, $AuZn_{3}$ IMCs were formed at the interface. In the case of the Au/Ni/Cu substrate, an $AuZn_{3}$ IMC layer formed at the interface due to the fast reaction between Au and Zn. In addition, the $AuZn_{3}$ IMC layer became detached from the interface after reflow. When the aging time was extended to 100 h, $Ni_{5}Zn_{21}$ IMC was observed on the Ni substrate.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.406-406
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• 2012

ZnO는 큰 여기자 결합 에너지, 낮은 유전 상수, 높은 화학적 안정도를 가지고 있기 때문에 전자소자 및 광소자로 많이 응용되고 있다. 여러 가지 불순물을 주입하여 ZnO의 전기적 및 광학적 성질을 향상시키기 위한 연구가 진행되고 있다. 여러 가지 불순물 중에 Zn와 물리적 및 화학적 성질이 유사한 Cu를 도핑하여 전기화학적성장(electrochemical deposition) 방법으로 ITO가 코팅된 유리 기판 위에 ZnO 박막을 성장하였다. Cu를 도핑하여 ZnO박막을 성장한 결과 구조적으로 ZnO 박막이 나노로드 형태에서 부분적으로 나노세선 또는 나노로드 형태로 변화함을 확인하였다. 광류미네센스 측정 결과는 벌크 ZnO 박막과 비교하여 Cu를 도핑함으로써 ZnO 나노세선이 3.37 eV의 에너지를 가지는 파장의 크기가 줄어들었고 여러 방향으로 ZnO 나노세선이 형성됨을 알 수 있었다. Cu를 도핑함으로써 ZnO 나노세선의 구조적 변화는 크기 않으나 에너지 밴드갭을 변화할 수 있음을 알 수 있었다. ZnO 나노세선의 광학적 성질을 Cu를 도핑하여 변화할 수 있음을 관측하였으며 불순물을 도핑하여 밴드갭을 변화하여 전자소자 및 광소자를 제작하는 기초지식으로 사용할 수 있다.

• Journal of Nutrition and Health
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• v.24 no.6
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• pp.516-525
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• 1991

In order to investigate whether serum Cu, Zn and Cu/Zn ratio are the useful indicater for the diagnosis of cancer. serum Cu and Zn levels were determined from 35 normal subjects and 33 stomach cancer patients by Atomic absorption spectrophotometer. The following results are obtained : Serum copper levels of stomach cancer patients were significantly increased than the those of the normal controls. whereas serum Zn levels significantly decreased than those of the normal contros(P<0.01) Therefore the copper to zinc ratio revealed a significant in the serum Cu and Zn levels. The serum protein and albumin levels were significantly lower in cancer patients(P<0.01) And the correlation analysis indicated that there was no significant correlation between serum Cu/Zn ratio and protein or albumin. These data suggest that the serum Cu. Zn and Cu/Zn ratio may be used as a diagnostic test in stomach cancer patients.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.121-124
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• 1998

Generally the structure of powder electroluminescent devices (PELDs) on ITO-film was makeup of the ZnS:Cu phosphor layer and BaTiO$_3$ insulating layer. The active layer, which consists of a suitably doped ZnS powder mixed in a dielectric, is sandwiched between two electrodes; one of which are ITO film and the other is aluminum. In this paper, three kinds of powder eleotroluminescent devices (PELDs) : WK-A(ITO/BaTiO$_3$/ZnS:Cu/Silver paste). WK-B(ITO/BaTiO$_3$+ZnS:Cu/Silver paste) and WK-C(ITO/BaTiO$_3$/ZnS:Cu/BaTiO$_3$/Silver paste), fabricated by spin coating method, were investigated. To evaluate the luminescence properties of three kinds of PELDs, EL emission spectroscopy, transferred charge density and time response of EL emission intensity under square wave voltage driving were measured.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.2
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• pp.105-114
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• 2004

This pot experiment was. conducted to investigate the effects of systematic variation application of Fe, Mn, Cu, and Zn on forage performance of orchardgrass and white clover. The treatments of systematic variation were 0/100, 25/75, 50/50, 75/25, and 100/0％ in the Fe/Cu(trial-1), Mn/Zn(trial-2), and Fe + Cu/Mn + Zn(trial-3), respectively. The treatments of Fe/Mn/Cu/Zn(trial-4) were composed of 70％ in main element and 10％ in other 3 elements, respectively. 1. In general, the unbalanced applications of Fe and Mn resulted in the Mn and Fe deficiencies(chlorosis) on white clover, respectively, because of the antagonism between Fe and Mn. In white clover, the traits of growth, root/nodule, and flowering, which were influenced by the systematic variation of Fe, Mn, Cu, and Zn, were closely correlated to each other. In the Fe/Cu trial, the 0/100 and 25/75 induced a Fe-deficiency on white clover, and the 0/100 also showed poor root growth and flowering. In addition, the 50/50 and 75/25 showed an early flowering of white clover. 2. In the Mn/Zn trial, the 0/100 induced a severe Mn-deficiency(chlorosis) on white clover. The 25/75 and 50/50, however, diminished the chlorosis symptom. The 75/25 and 100/0 showed generally good root growth and flowering of white clover. 3. In the Fe + Cu/Mn + Zn trial, the 0/100 induced a Fe-deficiency, and the 100/0 induced a Mn-deficiency on white clover, which were correlated to the poor root growth and flowering. The 75/25 showed good root growth and flowering of white clover. 1be flowering of white clover tended to be more influenced by the Fe + Cu than by the Mn + Cu ratios. 4. In the Fe/Mn/Cu/Zn trial, the Fe and Mn deficiencies on white clover, which were influenced by the Mn and Fe treatments, also occurred. The Cu and Zn-deficiency symptoms, however, were not recognized. General differences have been showed in the numbers of flowers as following orders; Zn > Cu > Mn > Fe - 70% treatments.